/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.values;



import com.bff.gaia.unified.sdk.annotations.Internal;

import com.bff.gaia.unified.sdk.coders.ByteArrayCoder;

import com.bff.gaia.unified.sdk.coders.Coder;

import com.bff.gaia.unified.sdk.coders.StructuredCoder;

import com.bff.gaia.unified.sdk.transforms.DoFn;

import com.bff.gaia.unified.vendor.guava.com.google.common.base.MoreObjects;



import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.util.Arrays;

import java.util.List;

import java.util.Objects;



/**

 * <b>For internal use only; no backwards compatibility guarantees.</b>

 *

 * <p>Immutable struct containing a value as well as a unique id identifying the value.

 *

 * @param <ValueT> the underlying value type

 */

@Internal

public class ValueWithRecordId<ValueT> {

  private final ValueT value;

  private final byte[] id;



  public ValueWithRecordId(ValueT value, byte[] id) {

    this.value = value;

    this.id = id;

  }



  public ValueT getValue() {

    return value;

  }



  public byte[] getId() {

    return id;

  }



  @Override

  public String toString() {

    return MoreObjects.toStringHelper(this).add("id", id).add("value", value).toString();

  }



  @Override

  public boolean equals(Object other) {

    if (this == other) {

      return true;

    }

    if (!(other instanceof ValueWithRecordId)) {

      return false;

    }

    ValueWithRecordId<?> otherRecord = (ValueWithRecordId<?>) other;

    return Objects.deepEquals(id, otherRecord.id) && Objects.deepEquals(value, otherRecord.value);

  }



  @Override

  public int hashCode() {

    return Objects.hash(Arrays.hashCode(id), value);

  }



  /** A {@link Coder} for {@code ValueWithRecordId}, using a wrapped value {@code Coder}. */

  public static class ValueWithRecordIdCoder<ValueT>

      extends StructuredCoder<ValueWithRecordId<ValueT>> {

    public static <ValueT> ValueWithRecordIdCoder<ValueT> of(Coder<ValueT> valueCoder) {

      return new ValueWithRecordIdCoder<>(valueCoder);

    }



    protected ValueWithRecordIdCoder(Coder<ValueT> valueCoder) {

      this.valueCoder = valueCoder;

      this.idCoder = ByteArrayCoder.of();

    }



    @Override

    public List<? extends Coder<?>> getCoderArguments() {

      return Arrays.asList(valueCoder);

    }



    @Override

    public void encode(ValueWithRecordId<ValueT> value, OutputStream outStream) throws IOException {

      encode(value, outStream, Context.NESTED);

    }



    @Override

    public void encode(ValueWithRecordId<ValueT> value, OutputStream outStream, Context context)

        throws IOException {

      valueCoder.encode(value.value, outStream);

      idCoder.encode(value.id, outStream, context);

    }



    @Override

    public ValueWithRecordId<ValueT> decode(InputStream inStream) throws IOException {

      return decode(inStream, Context.NESTED);

    }



    @Override

    public ValueWithRecordId<ValueT> decode(InputStream inStream, Context context)

        throws IOException {

      return new ValueWithRecordId<>(

          valueCoder.decode(inStream), idCoder.decode(inStream, context));

    }



    @Override

    public void verifyDeterministic() throws NonDeterministicException {

      valueCoder.verifyDeterministic();

    }



    public Coder<ValueT> getValueCoder() {

      return valueCoder;

    }



    Coder<ValueT> valueCoder;

    ByteArrayCoder idCoder;

  }



  /** {@link DoFn} to turn a {@code ValueWithRecordId<T>} back to the value {@code T}. */

  public static class StripIdsDoFn<T> extends DoFn<ValueWithRecordId<T>, T> {

    @ProcessElement

    public void processElement(ProcessContext c) {

      c.output(c.element().getValue());

    }

  }

}